The Haymond Formation
exposed within the Marathon Basin contains blocks and boulders derived
from at least three different source areas. Uniformitarian geologists
have proposed several different depositional settings in an effort to
understand the origin of these blocks and associated boulder beds. This
article reviews those models, explains their shortcomings, and proposes
a solution within the framework and time frames of the Young-Earth Flood
model. We propose that these blocks and boulders were locally derived
and subaqueously deposited during the global Flood, within at least
two different yet related settings: 1) as boulders within turbidity-currents,
2) and as slump and/or slide blocks derived from the rim of the basin
and from upturned thrust blocks due to tectonism associated with the
Ouachita Orogeny (viewed as a Flood tectonic event).

The Haymond Formation
found within the Marathon Basin in southwest Texas, has been the subject
of numerous uniformitarian investigations, spanning many decades (Figure
1) .As a stratigraphic unit, the Haymond Formation contains individual
layers composed of large-scale blocks and associated boulder beds of
enigmatic origin. The block and boulder beds primarily occur around
the rim of the basin and in the area adjacent to Housetop Mountain (Figures
2 and 3). Various studies have been conducted in an attempt to comprehend
the depositional and paleoenvironmental setting in which these sediments
were originally formed. Recently, creationists have brought these depositional
models under scrutiny in an attempt to determine their applicability
within the Young-Earth Flood model (Froede, Williams, Howe, and Goette,
1998;Howe and Williams, 1994; 1995).

Figure 2 - Housetop Mountain. Around the base
of this flat-topped mesa lie isolated outcrops of boulder beds derived
from still unknown source areas. We believe that these boulders
were derived via erosion and transportation from upland source areas
which were to the south and east of the Marathon Basin during the
Flood.

Figure 3 - Isolated blocks of rock believed
to be Haymond Flysch boulders. We were unable to closely examine
these boulders. This photograph was shot with a telephoto lens.
Blocks are estimated as being on the order of six to ten feet in
diameter. These boulders lie less than one-half mile from the base
of House Top Mountain.

Several uniformitarian
geologists have proposed that some strata within the Marathon Basin
ref1ect turbidity-current deposition (Denison, Kenny, Burke, and Hetherington,
1969; King, 1978; McBride, 1966; Thomson and McBride, 1964). Many creationists
would agree, but add that the majority of the strata within the Marathon
Basin was locally tectonically derived and was deposited via Flood generated
turbidity-currents.Footnote

Previously, Howe and Williams
(1995) reported on a section of the Haymond Formation called the Housetop
Mountain Boulder Beds Member. They described its alternating layers
of turbidity-current-derived flysch, composed of arkose, conglomerates,
and boulder- bearing mudstone. Their report centered on the twofold
nature of the boulder beds in mudstone strata: (1) large fragments of
limestone and novaculite and (2) smaller cobbles of igneous and metamorphic
origin. They concluded that the energy needed to deposit the boulders
and blocks (some up to 40 feet in size), within such mudstone beds supports
a high-energy (catastrophic) depositional setting. This mixture of cobbles
and boulders within the mud matrix is identified as wildflysch. Limestone
and other large boulders in the wildflysch apparently came from considerable
distances away from the place of final deposition, and the source of
the smaller exotic cobbles remains unknown (Howe and Williams, 1995).

This article will examine
several depositional models that have been proposed by uniformitarian
geologists in an attempt to explain how the Haymond Formation wildflysch
formed. We will comment on the numerous shortcomings provided by these
theories in addressing the block and associated boulder beds. Additionally,
we will provide a valid and defensible solution to the possible origins
of the Haymond Formation wildflysch, within the framework of the Young-
Earth Flood Model.

Possible
Origins of the Haymond Formation Boulder Beds

From 1931 to 1975, uniformitarian
geologists evaluated the Haymond Formation wildflysch layers and promoted
widely diverse theories about their origin, and method of emplacement.
Advocates of each hypothesis marshaled various items of supporting evidence
in an effort to address the physical evidence. What follows is an examination
and evaluation of several of these uniformitarian theories.

A Glacial Theory

According to Baker (1932, pp. 598, 602) there are at least nine characteristics
of the boulder beds that support a glacial mechanism of emplacement.
He noted that ice, not water, would produce a deposit that is unsorted,
like these boulder beds. Baker also asserted that ice would have been
capable of moving even the largest of the sedimentary blocks. The flysch
interbeds (layers above and below the boulder beds) had "...a typical
varve structure" which would likewise fit with Baker's idea that
these strata were glacially formed (1932, pp. 579-580).

Perhaps the strongest evidence favoring possible glacial deposition
are the scouring, cross-striations, and percussion marks which Baker
(1932, pp. 586, 588) found on certain exotic cobbles. The flattening
(known as soling) was most pronounced on certain quartzite and chert
cobbles that contained from one to seven flattened surfaces on a given
rock. According to Baker (1932, pp. 595-596), soling occurred when the
rocks were held in ice (which temporarily prevented them from changing
position) while they were being flattened. He admitted, however, that
soling could have been caused by faulting or by "interstitial movement"
in the rocks.

Carney (1934, p. 70) wrote a brief note in which he too affirmed a
glacial mechanism. He called the boulder beds "tillites" of
"aqueoglacial" origin. From the mid-1920's throughout the
1930's it was common for uniformitarian geologists to attribute the
transport of large boulders in boulder beds to a glacial setting (see
also Powers, 1928, p. 1046).

The Glacial Mechanism Evaluated

Problems with the glacial model became apparent when this evidence
was more closely examined and compared to other similar settings. The
number of soling marks and other indicators of glacial activity on the
boulders/blocks within the Haymond Formation were found to be lacking
for the most part. The few features that did exist could have been produced
by mudflows or other mechanisms. Crowell (1957, p.993) noted that episodes
of glaciation may have been wrongly proposed, based on the assumption
that such marks are necessarily caused by glaciers:

In fact, some glacial episodes may have been introduced into geologic
history based on the interpretation of such rocks as tillites without
independent supporting evidence. Such "tillites" should
therefore be restudied, for they may have originated by slumping and
mixing of interbedded gravel and mud precontemporaneously with deposition.

It is worth noting that Lehman (1945) rejected a similar glacial transport
setting for erratic masses of rock in the Arbuckle Mountains of Oklahoma.
At present there is little support for the idea that the Marathon Basin
experienced glaciation at anytime in the past.

It is the contention of Oard (1997) that none of the" evidence
for worldwide Pre-Pleistocene glaciation is compelling. Rather, he has
proposed (and we agree) that the physical evidence used to support glaciation
is better explained by invoking large-scale submarine landslides globally
within the framework of the Flood of Genesis. We applaud Oard's work
and find it directly applicable to the Haymond Formation wild-flysch.

A Mudflow Theory

King (1937, p. 91) asserted that all evidence for glacial origins "
. . . could equally well be interpreted as the work of mud flows."
He cited reports from California and Nevada in which gigantic blocks"
. . . as large as most of those in the Haymond formation" (King
1937, p. 91) had been transported for many miles in mud-filled streams.

King also argued that the boulders in the Housetop Mountain beds were
not transported by flowing water because the boulders are "intraformational"
(occurring throughout a single stratum) while boulders in water- formed
conglomerates are ordinarily "basal " - occurring at the bottom
of a stratum only (King, 1937, p. 90) .The mudstone layers are found
repeatedly throughout a thickness of about 275 m (see Howe and Williams,
1995, Figure 11). The presence of a mudstone is itself strong evidence
favoring a mudflow origin.

Tectonism versus Mudflows: A Published Debate

There was a hiatus in the literature (perhaps related to World War
II) from the late 1930s to the middle 1950s, after which interest again
centered on the boulder beds. Hall (1956, p. 2254) first referred to
tectonism as the sole cause of the boulder beds. In concluding a paper
on orogeny, Hall (1956, p. 2254) remarked that:

A year later Hall (1957, pp. 1633-1634 ) further suggested that the
large sedimentary fragments were derived from the denuded cores of faulted
folds. He proposed that the boulders were not transported and bedded,
but fault breccia and outcrops of Paleozoic strata brought to their
present location by faulting and folding. Hall pointed to breccia in
the Housetop Mountain beds as a clear indication of their tectonic origin
(Hall, 1957, p. 1635). Some of the breccia was even further brecciated,
suggesting two separate fault movements.

Commenting on Hall's tectonic model, King (1958) noted that the idea
these beds are the remnants of faulted folds had been previously considered
by several investigators, but was discarded based on a detailed examination
of the boulder bed strata. King (1958, p. 1733) admitted that many of
the large novaculite and chert boulders were brecciated but he asserted
that the brecciation:

. . . occurred before they arrived at their present positions: .
. . cherts and novaculites were faulted in situ before or during
deposition of the boulder beds.

Flawn (1958) sided with King, expressing disagreement with Hall's idea
that the large boulders are merely the eroded remnants of faulted cores.
Flawn pointed to the interspersion of igneous and metamorphic cobbles
in these same beds as support for a mud flow rather than simple tectonic
origin (1958, p. 1735).

The published dialogue ended in 1959 when Hall repeated his view that
the "big boulders" are merely the in situ remnants
of previous tectonism. He conceded, however, that the smaller metamorphic
and igneous rocks might have been added later by a mudflow (Hall, 1959,
p. 239).

Through the 1960's and 1970's, McBride elaborated on the evidence used
to support the concept of gigantic mudflows as the agency of deposition
(1964; 1966; 1969a; 1970; 1978). He envisioned a deep-water turbidity
current depositional environment as the setting for the Haymond Formation,
including the boulder beds. He proposed that major mudflows originated
as the product of submarine slides triggered by earthquakes.

We believe that King, Flawn, and McBride are correct in arguing that
the blocks and boulder beds cannot be explained as merely the in
situ remnants of faulted and eroded ridges. The large blocks are
not connected to any adjacent formation but are completely surrounded
by the mudstone matrix.

Catastrophic Tectonism As The Source of the Large Boulders

While it appears unlikely that the giant boulders are the remnants
of faulted folds; many of the geologists who have worked on the Haymond
Formation boulder beds saw a diastrophic source for the Pennsylvanian
limestone blocks. Sellards (1931, p. 18) proposed that the largest boulders,
which he called "erratics" are:

. . . evidence of uplifts, mountainous in character, adjacent to
the Marathon region . . . The erratics, therefore are evidence of
mountain-making movements affecting the ancient land masses lying
to the south and east of the Marathon region.

He believed that these limestone fragments originated by way of folding
and overthrusting. Baker (1932, p. 593) likewise proposed that there
was an original diastrophism which is reflected in the underlying Tesnus
deposits, and then a second diastrophic event that brought on the "Haymond
deposition":

A second epoch of diastrophism, or the extension of diastrophism
farther northwest, is demonstrated by the boulder deposits of the
Haymond. This diastrophism was intense, since the novaculite was greatly
deformed before boulders derived from it were deposited in the Haymond,
and there must have been land of high relief. to furnish the extremely
coarse detritals from the thick suspension of rocks which are found
in the Haymond boulder beds.

King, Baker, and Sellards (1931) wrote about the uplift of a source
area in west Texas, probably to the south of the present day boulder
beds. They expressed the belief that the boulders were produced and
moved by diastrophism and uplift, not by streams, currents, or landslides.
King (1937) envisioned overthrusts on the Hell's Half Acre fault (south
and southeast of Marathon Basin) as a southeasterly source of the large
boulders. More recent work conducted by Palmer, Demis, Muehlberger,
and Robison (1984) supports this southeasterly source.

Tectonism May Have Produced the Basin

Ross wrote of thrust faulting as providing the mechanism for the development
of the Marathon Basin. He de scribed the northwestward growth of a series
of shallow marine shelves by tectonic movements. These shallow shelves
were progressively thrust northwestward, one over the other. At this
time, a trough called a "fore-deep" was formed:

The general relationships are such that the uplifted and deformed
sediments of the geosynclinal facies were progressively thrust northward
in a series of steps onto the craton and that the weight of the thrusted
materials caused the depression of the craton margin to give rise
to a narrow fore-deep which, in turn, received deepwater turbidites,
black shales, and related deposits (Ross, 1981, p. 135).

King (1958, p. 1734) referred to the Marathon Basin as a deep, rapidly
subsiding trough. Even as late as 1978, King still believed that the
flysch sequence (including the boulder beds) were created by:

. . . quickening tectonic activity. An exaggerated phase is the wild-flysch
of the Haymond, whose small to giant clasts were derived partly from
uplifts within the trough, and partly from the foreland and backland
(p. 5).

A Second Debate: Deep Water Turbidity Mudflows Versus
Short Headed Stream Deltas

McBride (1966) claimed that deep-water turbidity currents produced
the Haymond flysch with its wild- flysch beds. In 1970, Flores and Ferm
attempted to show that the Haymond interbeds were deposited in the shallow
water of prograding deltas. Flores attributed various portions of the
Haymond Formation to delta-front, delta, or delta plain sedimentation
(Flores, 1975a, pp. 2299- 2301). In Flores' view (1975a, p. 2294), the
boulder beds were formed in a small cul-de-sac of slack water where
deposition occurred only during periods of high-energy run-off:

. . . the Housetop middle-upper interval of black carbonaceous shale,
gravelly siltstone, bouldery beds, and conglomerate probably represented
deposits of cul-de-sac of slack water on the delta plain which was
reached only during periods of greatest runoff and high-velocity currents.

Flores and Ferill (1970) presented what they believed to be a contemporary
example of a delta model for boulder bed genesis in a short-headed stream
(Canadaway Creek, New York) that flows into Lake Erie. Flores (1975a,
p. 2297) summarized this delta-related boulder bed analogue by noting
that the:

. . . Devonian and Pleistocene deposits are incised by short-headed
streams (average of 50 km) with steep gradients. The narrow valleys
are choked with gravels including boulders which are flushed downstream
into small deltas during periods of high runoff some of the large
boulders simply sink into the salty to sandy nearshore deposits

Flores and Ferm (1970, p. 626) attributed the large accumulation of
boulders in the walled valleys of the river to "episodes of heavy
rainfall, and reworking of headland and wave cut scree detritus."
They believed that " . . . the Lake Erie model may supply a reasonable
approximation of the Haymond sedimentary conditions."

In the same year that Flores and Ferm released their views concerning
Canadaway Creek, McBride promoted a river in France (the Var) as a modern
analogue for a deep-water turbidite mudflow mechanism. McBride (1970,
p. 80) asserted that where the Var River enters the Atlantic Ocean it
demonstrates how the Haymond boulder beds may have formed:

. . . the blocks and associated finer debris were carried in submarine
slumps, debris flows, and mudflows from shallow water into deeper
water. The huge rocks churned through unconsolidated sandstone and
shale beds and generated mudstone that helped carry the blocks further.
The occurrence of chert and novaculite breccias and the presence of
formations that normally lie 1,000 to 3,000 m stratigraphically below
the boulder beds suggests the fragments were derived from thrust sheets.
. .

McBride envisioned thrust sheets as the source for the large sedimentary
blocks, and he believed that the boulder beds formed within turbidity
currents operating in deep water. The debate between Flores and McBride
on the issue of possible depositional settings for the block and boulder
beds occurred again in 1975, with no further resolution (McBride, 1975;
Flores, 1975b).

In an effort to recognize Flores' work, King (1975, p. 8) suggested
that certain sandstone beds in the upper half of the Haymond
may have been formed on a delta:

Flores proposes that these are delta front and delta-plain deposits;
this is plausible, as by late Haymond time the flysch trough had been
nearly filled, especially along its northern margin.

In our evaluation of the two depositional settings, we agree with the
position advocated by McBride that the preponderance of evidence used
to define the Haymond Formation, is better supported invoking turbidity
current deposition for the majority of the Haymond Formation wildflysch
and blocks. In our catastrophic scenario, a few rapidly prograding delta-fed
deposits could have formed at the top of the Marathon Basin stratigraphic
sequence. However, we do not believe that a typical "uniformitarian"
delta by its own actions could form the block and boulder beds of the
Haymond flysch deposits as Flores has suggested.

*This table provides a summary of the maximum size of blocks and boulders
encountered within the Haymond Formation (from across the basin). We
would agree with the uniformitarians that these blocks and boulders
are derived due to orogenic processes associated with the Ouachita Orogeny.
We also agree that these blocks and boulders were derived from massive
upturned strata which were faulted, thrusted over one another, and whose
exposed upper surfaces were eroded into the adjacent Marathon basin.
However, we believe that all of this happened rapidly during the Flood-based
Ouachita Orogeny. Information within this table is derived from Denison
et al., (1969, p. 246), McBride (1966, p. 26), and Palmer et
al., (1984, p. 91).

Boulder/Block Source and Transportation Problems

Recent studies within the Marathon Basin, regarding the composition
and age of the various boulders and blocks found within the Haymond
wildflysch, have raised even greater confusion about their possible
source areas and transport distances. According to Palmer et al.,
(1984, p. 94), there are three populations (see Table I) of boulders
within the Haymond flysch:

In 1969, Denison et al., reported on the radioactive isotope
dating of igneous and metamorphic boulders collected from the Haymond
Formation. Their results determined that the source of the igneous and
metamorphic boulders could not be clearly defined within the local area
immediately around the basin (based on comparing rocks with presumed
similar age-dates). They also examined outcrops of similar types of
igneous and metamorphic rocks from as far away as 300 miles to the south
(in Mexico) and 100 miles to the west (Texas and Mexico), and found
nothing which yielded similar age-dates (using the Rubidium-Strontium
dating method). It was concluded that the source for these Haymond Formation
boulders could not be identified (Denison et al., 1969, p. 245). In
attempting to determine the travel distance of these igneous and metamorphic
boulders, Denison et al., (1969, p. 250) stated:

A germane question is the distance which boulders of this type and
size in the Haymond Formation can be transported. The answer cannot
be strictly quantitative, but the distance is certainly considerably
in excess of 100 miles.

In a more recent paper on the boulder beds, Palmer et al., (1984)
identified limestone boulders within certain areas of the Haymond wildflysch
that contained well preserved phosphatic fossils of Middle Cambrian
trilobites and brachiopod taxa. It is interesting to note that they
could not account for the source of these limestone boulders, although
the fossils correspond directly to those found:

. . . not only from Utah but also from Alaska, northern Greenland,
Quebec, and the southern Appalachians (Palmer et al., 1984,
p. 91).

However, no source for the unmetamorphosed Cambrian boulders is apparent,
and their parent rocks were originally southeast of the present location
of the Devil's River uplift (approximately 125 miles to the southeast).
The limited age range of these boulders suggests that they may have
come from a tectonic slice. (Parenthesis ours)

To account for these fossil-rich Middle Cambrian limestone boulders
uniformitarians appeal to uplifted and thrusted blocks adjacent to the
Marathon Basin (southeast). However, none of the original in situ limestone
strata outcrop in or around the basin, in any of the upturned strata.
The fossiliferous Middle Cambrian limestone source area remains unidentified.

While we do not think it unreasonable to invoke "a tectonic slice"
origin for the fossiliferous Middle Cambrian limestone, it does appear
to require tectonism and erosion at a far greater rate than is currently
recognized within the uniformitarian model. The Middle Cambrian fossiliferous
limestone is unmetamorphosed, which implies shallow burial, and that
it experienced little to no heat or pressure. Yet the source strata
for this limestone is projected as being approximately 125 miles away
(Palmer et al., 1984, p. 93) and several thousand feet beneath
the surface. Hence, in order to account for the presence of the limestone
boulders within the Haymond Formation the limestone source must have
moved 125 miles northwestward, while experiencing tectonic uplift and
thrusting, followed by rotation, erosion, transport, and deposition
(within a turbidity-current setting). This speaks of large-scale catastrophism.
An alternative uniformitarian interpretation might suggest that the
limestone boulders were derived from sources around western Utah and
then transported approximately 870 miles!

Viewed individually, the sedimentary blocks and boulder beds present
a seemingly minor problem to the uniformitarian model. However, the
required large-scale tectonism coupled with a deep-water turbidity-current
depositional setting creates problems that we believe are insurmountable.
Invoking millions of years of slow uniformitarian tectonism (both compression
and uplift), erosion, transportation, and deposition within a deep-
water turbidity-current paleoenvironment requires much imagination and
no common sense! For example, many of the wildflysch boulders found
within the Haymond Formation could not have traveled very far without
being destroyed (Figures 2 and 3). Creationist studies into such matters
supports this claim (Chui, 1997, 1998). Yet, uniformitarians tell us
that many of these blocks and boulders traveled potentially tens to
hundreds of miles.

The authors believe that the stratigraphic evidence (beds, translational
slides/slumps, and exotic boulders) suggests that the Haymond Formation
formed under catastrophic forces and process which operated during the
global Flood of Genesis (see Froede et al., 1998, Figure 2, p.
96) .The massive blocks and exotic boulders found within the Haymond
Formation turbidites are easily explained as the remains of broken blocks
or slump blocks which were derived from eroded up-dip source areas (see
Morgenstern, 1967) during the Flood. Tectonism in operation during the
Flood create source areas immediately adjacent to the Marathon Basin,
and these locally- derived blocks and boulders simply moved under gravitation
into the basin (Froede et al., 1998). These clasts and megaclasts
were then rapidly buried under additional turbidites also derived from
nearby source areas that experienced tremendous erosion and transport
during the Flood (Figures 4 and 5).

Figure 4. Boulders of Novaculite Chert found
within the Haymond Formation turbidites exposed along U.S. Highway
385, approximately 600 feet north of the intersection with U.S.
Highway 90, just east of the city of Marathon (Location 1 in Figure
1). Note the one massive chert boulder on the left side of the photograph.
The scale to the right of that boulder is three feet long, divided
in six-inch units. Several other rounded chert boulders can be seen
within the strata.

Figure 5. Various boulders of Novaculite Chert
exposed in the turbidite deposits of the Haymond Formation. A six-inch
scale rests on top of a chert boulder on the right side of the photograph.
A close examination of this photograph reveals several chert boulders.
Same locale as Figure 2.

Conclusion

Numerous ideas have been proposed by uniformitarian geologists in an
effort to explain the origin and depositional environment of the Haymond
Formation boulder beds. Our review noted a blend of three different
components: (1) experimentally based science, (2) uniformitarian philosophy,
and (3) origin by analogy. Concerning experimental science, various
workers have produced field and laboratory analyses of the lithology,
tectonics, stratigraphy, and even the chemistry of these boulder beds.
Woven into their technical scientific reports, however, is the philosophical
"immense periods of time" to which most geologists attempt
to tie their labors. Every uniformitarian geologist studying the Haymond
Formation has likewise attempted to deduce an "origin" model
involving glacial ice, tectonism, mudflows, prograding deltas, and/or
turbidity currents using the modern depositional environment analogy
as the most credible means to account for the block and associated boulders
beds.

We propose that the most plausible theory for the origin of the Haymond
Formation blocks and boulder beds exists within a turbidity-current
depositional setting. The greatest problem now facing uniformitarians
is to account for the different source areas of the three boulder populations
using uniformitarianism - it simply does not work. Rather, we believe
that the Marathon Basin and all of its in filling materials (sediments,
blocks and boulder beds) reflect the global Flood of Genesis.

We further believe that the stratigraphic record found within the Marathon
Basin represents high- energy erosional and depositional forces coupled
with short-period tectonism (the Flood-Event based Ouachita Orogeny).
These catastrophic forces and processes resulted in the emplacement
of locally-derived blocks, slumps, boulders, and mudflows (via turbidity
currents) into the Marathon Basin. This setting clearly fits within
the short-term high-energy framework expected within the global Flood.

Footnote:
A creationist overview of turbidity currents and their resulting deposits
can be found in Froede, 1998. Large-scale submarine debris flows, misidentified
as glacial deposits, are described and discussed in Oard, 1997.

__________ . 1978. Tectonics and sedimentation of the Paleozoic rocks
in the Marathon region, west Texas. In Mazzullo, S.J. (editor). Tectonics
and Paleozoic facies of the Marathon Geosyncline, west Texas. Field
conference guidebook for the Permian Basin Section of the Society of Economic
Paleontologists and Mineralogists. Publication No. 78-17. Midland, TX.
pp. 5-37.

Powers, S. 1928. Age of the founding of the Oklahoma Mountains--the Ouachita,
Arbuckle, Wichita Mountains of Oklahoma and the Llano-Burnet and Marathon
Uplifts of Texas. Geological Society of America Bulletin 39:1031-1072.

Ross, C.A. 1981. Pennsylvanian and Early Permian history of the Marathon
Basin, West Texas. In Permian Basin Section of the Society of Economic
Paleontologists and Mineralogists. Symposium and guidebook to the Marathon
-- Marfa Region of West Texas. pp. 135-144.

Sellards, E. H. 1931. Erratics in the Pennsylvanian of Texas. University
of Texas Bulletin 3101:9-17.

Thomson, A. and E.F. McBride. 1964. Summary of the geologic history of
the Marathon Geosyncline. In The filling of the Marathon Geosyncline.
Permian Basin Section of the Society of Economic Paleontologists and Mineralogists.
Midland, TX. pp. 52-60.